Process for the recovery of NO from the waste gas resulting from the production of ammonium nitrite
US4971776A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Aug 24, 1989 |
| Grant date | Nov 20, 1990 |
| Priority date | — |
| Expiry date | Aug 24, 2009 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY02P20/151
- WIPO fieldChemical engineering
- WIPO sectorChemistry
Abstract
A process for the complete recovery of NO from the waste gas of ammonium nitrite production, in which gases containing nitrogen oxides are absorbed in a first stage in a solution of ammonium carbonate and/or ammonium bicarbonate to form ammonium nitrite solutions and the resulting waste gas containing carbon dioxide is absorbed in a second stage in an ammoniacal, aqueous solution to form ammonium carbonate and/or ammonium bicarbonate which is returned as such to the first absorption stage, and the waste gas containing carbon dioxide is brought into contact with a sulphuric acid of medium concentration containing from 0.1-5% by weight, preferably from 0.2 to 1.5% by weight of nitric acid before the carbon dioxide is introduced into the second absorption stage.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.